public class inputKey {

  public static void printPrompt(String prompt) {
    System.out.print(prompt + " ");
    System.out.flush();
  }

  public static void inputFlush() {
    int dummy;
    int bAvail;

    try {
      while ((System.in.available()) != 0)
        dummy = System.in.read();
    } catch (java.io.IOException e) {
      System.out.println("Input error");
    }
  }

  public static String inString(String prompt) {
    inputFlush();
    printPrompt(prompt);
    return inString();
  }

  public static String inString() {
    int aChar;
    String s = "";
    boolean finished = false;

    while (!finished) {
      try {
        aChar = System.in.read();
        if (aChar < 0 || (char) aChar == '\n')
          finished = true;
        else if ((char) aChar != '\r')
          s = s + (char) aChar;
      }

      catch (java.io.IOException e) {
        System.out.println("Input error");
        finished = true;
      }
    }
    if(s.isEmpty()) {
		s = "<NA>";
	}
    return s;
  }

  public static int inInt(String prompt) {
    while (true) {
      inputFlush();
      printPrompt(prompt);
      try {
        return Integer.valueOf(inString().trim()).intValue();
      }

      catch (NumberFormatException e) {
        System.out.println("Invalid input. Not an integer");
      }
    }
  }

  public static char inChar(String prompt) {
    int aChar = 0;

    inputFlush();
    printPrompt(prompt);

    try {
      aChar = System.in.read();
    }

    catch (java.io.IOException e) {
      System.out.println("Input error");
    }
    inputFlush();
    return (char) aChar;
  }

  public static double inDouble(String prompt) {
    while (true) {
      inputFlush();
      printPrompt(prompt);
      try {
        return Double.valueOf(inString().trim()).doubleValue();
      }

      catch (NumberFormatException e) {
        System.out
            .println("Invalid input. Not a floating point number");
      }
    }
  }
}